as others have said, with the appropriate cleaner, you have nothing to worry about... don't use something like CLR or toilet bowl cleaner and you should be good to go... my wood smith runs my receivers through one every time I send him some work... he has the wood off anyways so its a great time to clean out the 100+ years of gunk...two things... you will need to lubricate your action again afterwards for sure... also, your gun may have been functioning with some of that gunk as part of the works...if the gun has not been reasonably cleaned in a LONG time, don't be surprised if the trigger pulls are harder, lever is slightly offset, etc
